diff options
Diffstat (limited to 'drivers/md/dm-crypt.c')
| -rw-r--r-- | drivers/md/dm-crypt.c | 345 |
1 files changed, 242 insertions, 103 deletions
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c index 0fce0bc1a95..4cba2d808af 100644 --- a/drivers/md/dm-crypt.c +++ b/drivers/md/dm-crypt.c @@ -1,7 +1,8 @@ /* - * Copyright (C) 2003 Christophe Saout <christophe@saout.de> + * Copyright (C) 2003 Jana Saout <jana@saout.de> * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org> * Copyright (C) 2006-2009 Red Hat, Inc. All rights reserved. + * Copyright (C) 2013 Milan Broz <gmazyland@gmail.com> * * This file is released under the GPL. */ @@ -18,7 +19,6 @@ #include <linux/crypto.h> #include <linux/workqueue.h> #include <linux/backing-dev.h> -#include <linux/percpu.h> #include <linux/atomic.h> #include <linux/scatterlist.h> #include <asm/page.h> @@ -38,12 +38,11 @@ struct convert_context { struct completion restart; struct bio *bio_in; struct bio *bio_out; - unsigned int offset_in; - unsigned int offset_out; - unsigned int idx_in; - unsigned int idx_out; + struct bvec_iter iter_in; + struct bvec_iter iter_out; sector_t cc_sector; atomic_t cc_pending; + struct ablkcipher_request *req; }; /* @@ -98,6 +97,13 @@ struct iv_lmk_private { u8 *seed; }; +#define TCW_WHITENING_SIZE 16 +struct iv_tcw_private { + struct crypto_shash *crc32_tfm; + u8 *iv_seed; + u8 *whitening; +}; + /* * Crypt: maps a linear range of a block device * and encrypts / decrypts at the same time. @@ -105,15 +111,7 @@ struct iv_lmk_private { enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID }; /* - * Duplicated per-CPU state for cipher. - */ -struct crypt_cpu { - struct ablkcipher_request *req; -}; - -/* - * The fields in here must be read only after initialization, - * changing state should be in crypt_cpu. + * The fields in here must be read only after initialization. */ struct crypt_config { struct dm_dev *dev; @@ -139,16 +137,11 @@ struct crypt_config { struct iv_essiv_private essiv; struct iv_benbi_private benbi; struct iv_lmk_private lmk; + struct iv_tcw_private tcw; } iv_gen_private; sector_t iv_offset; unsigned int iv_size; - /* - * Duplicated per cpu state. Access through - * per_cpu_ptr() only. - */ - struct crypt_cpu __percpu *cpu; - /* ESSIV: struct crypto_cipher *essiv_tfm */ void *iv_private; struct crypto_ablkcipher **tfms; @@ -171,7 +164,8 @@ struct crypt_config { unsigned long flags; unsigned int key_size; - unsigned int key_parts; + unsigned int key_parts; /* independent parts in key buffer */ + unsigned int key_extra_size; /* additional keys length */ u8 key[0]; }; @@ -184,11 +178,6 @@ static void clone_init(struct dm_crypt_io *, struct bio *); static void kcryptd_queue_crypt(struct dm_crypt_io *io); static u8 *iv_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq); -static struct crypt_cpu *this_crypt_config(struct crypt_config *cc) -{ - return this_cpu_ptr(cc->cpu); -} - /* * Use this to access cipher attributes that are the same for each CPU. */ @@ -230,6 +219,16 @@ static struct crypto_ablkcipher *any_tfm(struct crypt_config *cc) * version 3: the same as version 2 with additional IV seed * (it uses 65 keys, last key is used as IV seed) * + * tcw: Compatible implementation of the block chaining mode used + * by the TrueCrypt device encryption system (prior to version 4.1). + * For more info see: http://www.truecrypt.org + * It operates on full 512 byte sectors and uses CBC + * with an IV derived from initial key and the sector number. + * In addition, whitening value is applied on every sector, whitening + * is calculated from initial key, sector number and mixed using CRC32. + * Note that this encryption scheme is vulnerable to watermarking attacks + * and should be used for old compatible containers access only. + * * plumb: unimplemented, see: * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454 */ @@ -530,7 +529,7 @@ static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv, char ctx[crypto_shash_descsize(lmk->hash_tfm)]; } sdesc; struct md5_state md5state; - u32 buf[4]; + __le32 buf[4]; int i, r; sdesc.desc.tfm = lmk->hash_tfm; @@ -608,6 +607,153 @@ static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv, return r; } +static void crypt_iv_tcw_dtr(struct crypt_config *cc) +{ + struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; + + kzfree(tcw->iv_seed); + tcw->iv_seed = NULL; + kzfree(tcw->whitening); + tcw->whitening = NULL; + + if (tcw->crc32_tfm && !IS_ERR(tcw->crc32_tfm)) + crypto_free_shash(tcw->crc32_tfm); + tcw->crc32_tfm = NULL; +} + +static int crypt_iv_tcw_ctr(struct crypt_config *cc, struct dm_target *ti, + const char *opts) +{ + struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; + + if (cc->key_size <= (cc->iv_size + TCW_WHITENING_SIZE)) { + ti->error = "Wrong key size for TCW"; + return -EINVAL; + } + + tcw->crc32_tfm = crypto_alloc_shash("crc32", 0, 0); + if (IS_ERR(tcw->crc32_tfm)) { + ti->error = "Error initializing CRC32 in TCW"; + return PTR_ERR(tcw->crc32_tfm); + } + + tcw->iv_seed = kzalloc(cc->iv_size, GFP_KERNEL); + tcw->whitening = kzalloc(TCW_WHITENING_SIZE, GFP_KERNEL); + if (!tcw->iv_seed || !tcw->whitening) { + crypt_iv_tcw_dtr(cc); + ti->error = "Error allocating seed storage in TCW"; + return -ENOMEM; + } + + return 0; +} + +static int crypt_iv_tcw_init(struct crypt_config *cc) +{ + struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; + int key_offset = cc->key_size - cc->iv_size - TCW_WHITENING_SIZE; + + memcpy(tcw->iv_seed, &cc->key[key_offset], cc->iv_size); + memcpy(tcw->whitening, &cc->key[key_offset + cc->iv_size], + TCW_WHITENING_SIZE); + + return 0; +} + +static int crypt_iv_tcw_wipe(struct crypt_config *cc) +{ + struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; + + memset(tcw->iv_seed, 0, cc->iv_size); + memset(tcw->whitening, 0, TCW_WHITENING_SIZE); + + return 0; +} + +static int crypt_iv_tcw_whitening(struct crypt_config *cc, + struct dm_crypt_request *dmreq, + u8 *data) +{ + struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; + u64 sector = cpu_to_le64((u64)dmreq->iv_sector); + u8 buf[TCW_WHITENING_SIZE]; + struct { + struct shash_desc desc; + char ctx[crypto_shash_descsize(tcw->crc32_tfm)]; + } sdesc; + int i, r; + + /* xor whitening with sector number */ + memcpy(buf, tcw->whitening, TCW_WHITENING_SIZE); + crypto_xor(buf, (u8 *)§or, 8); + crypto_xor(&buf[8], (u8 *)§or, 8); + + /* calculate crc32 for every 32bit part and xor it */ + sdesc.desc.tfm = tcw->crc32_tfm; + sdesc.desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP; + for (i = 0; i < 4; i++) { + r = crypto_shash_init(&sdesc.desc); + if (r) + goto out; + r = crypto_shash_update(&sdesc.desc, &buf[i * 4], 4); + if (r) + goto out; + r = crypto_shash_final(&sdesc.desc, &buf[i * 4]); + if (r) + goto out; + } + crypto_xor(&buf[0], &buf[12], 4); + crypto_xor(&buf[4], &buf[8], 4); + + /* apply whitening (8 bytes) to whole sector */ + for (i = 0; i < ((1 << SECTOR_SHIFT) / 8); i++) + crypto_xor(data + i * 8, buf, 8); +out: + memset(buf, 0, sizeof(buf)); + return r; +} + +static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv, + struct dm_crypt_request *dmreq) +{ + struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; + u64 sector = cpu_to_le64((u64)dmreq->iv_sector); + u8 *src; + int r = 0; + + /* Remove whitening from ciphertext */ + if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) { + src = kmap_atomic(sg_page(&dmreq->sg_in)); + r = crypt_iv_tcw_whitening(cc, dmreq, src + dmreq->sg_in.offset); + kunmap_atomic(src); + } + + /* Calculate IV */ + memcpy(iv, tcw->iv_seed, cc->iv_size); + crypto_xor(iv, (u8 *)§or, 8); + if (cc->iv_size > 8) + crypto_xor(&iv[8], (u8 *)§or, cc->iv_size - 8); + + return r; +} + +static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv, + struct dm_crypt_request *dmreq) +{ + u8 *dst; + int r; + + if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) + return 0; + + /* Apply whitening on ciphertext */ + dst = kmap_atomic(sg_page(&dmreq->sg_out)); + r = crypt_iv_tcw_whitening(cc, dmreq, dst + dmreq->sg_out.offset); + kunmap_atomic(dst); + + return r; +} + static struct crypt_iv_operations crypt_iv_plain_ops = { .generator = crypt_iv_plain_gen }; @@ -643,6 +789,15 @@ static struct crypt_iv_operations crypt_iv_lmk_ops = { .post = crypt_iv_lmk_post }; +static struct crypt_iv_operations crypt_iv_tcw_ops = { + .ctr = crypt_iv_tcw_ctr, + .dtr = crypt_iv_tcw_dtr, + .init = crypt_iv_tcw_init, + .wipe = crypt_iv_tcw_wipe, + .generator = crypt_iv_tcw_gen, + .post = crypt_iv_tcw_post +}; + static void crypt_convert_init(struct crypt_config *cc, struct convert_context *ctx, struct bio *bio_out, struct bio *bio_in, @@ -650,10 +805,10 @@ static void crypt_convert_init(struct crypt_config *cc, { ctx->bio_in = bio_in; ctx->bio_out = bio_out; - ctx->offset_in = 0; - ctx->offset_out = 0; - ctx->idx_in = bio_in ? bio_in->bi_idx : 0; - ctx->idx_out = bio_out ? bio_out->bi_idx : 0; + if (bio_in) + ctx->iter_in = bio_in->bi_iter; + if (bio_out) + ctx->iter_out = bio_out->bi_iter; ctx->cc_sector = sector + cc->iv_offset; init_completion(&ctx->restart); } @@ -681,8 +836,8 @@ static int crypt_convert_block(struct crypt_config *cc, struct convert_context *ctx, struct ablkcipher_request *req) { - struct bio_vec *bv_in = bio_iovec_idx(ctx->bio_in, ctx->idx_in); - struct bio_vec *bv_out = bio_iovec_idx(ctx->bio_out, ctx->idx_out); + struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in); + struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out); struct dm_crypt_request *dmreq; u8 *iv; int r; @@ -693,24 +848,15 @@ static int crypt_convert_block(struct crypt_config *cc, dmreq->iv_sector = ctx->cc_sector; dmreq->ctx = ctx; sg_init_table(&dmreq->sg_in, 1); - sg_set_page(&dmreq->sg_in, bv_in->bv_page, 1 << SECTOR_SHIFT, - bv_in->bv_offset + ctx->offset_in); + sg_set_page(&dmreq->sg_in, bv_in.bv_page, 1 << SECTOR_SHIFT, + bv_in.bv_offset); sg_init_table(&dmreq->sg_out, 1); - sg_set_page(&dmreq->sg_out, bv_out->bv_page, 1 << SECTOR_SHIFT, - bv_out->bv_offset + ctx->offset_out); - - ctx->offset_in += 1 << SECTOR_SHIFT; - if (ctx->offset_in >= bv_in->bv_len) { - ctx->offset_in = 0; - ctx->idx_in++; - } + sg_set_page(&dmreq->sg_out, bv_out.bv_page, 1 << SECTOR_SHIFT, + bv_out.bv_offset); - ctx->offset_out += 1 << SECTOR_SHIFT; - if (ctx->offset_out >= bv_out->bv_len) { - ctx->offset_out = 0; - ctx->idx_out++; - } + bio_advance_iter(ctx->bio_in, &ctx->iter_in, 1 << SECTOR_SHIFT); + bio_advance_iter(ctx->bio_out, &ctx->iter_out, 1 << SECTOR_SHIFT); if (cc->iv_gen_ops) { r = cc->iv_gen_ops->generator(cc, iv, dmreq); @@ -738,16 +884,15 @@ static void kcryptd_async_done(struct crypto_async_request *async_req, static void crypt_alloc_req(struct crypt_config *cc, struct convert_context *ctx) { - struct crypt_cpu *this_cc = this_crypt_config(cc); unsigned key_index = ctx->cc_sector & (cc->tfms_count - 1); - if (!this_cc->req) - this_cc->req = mempool_alloc(cc->req_pool, GFP_NOIO); + if (!ctx->req) + ctx->req = mempool_alloc(cc->req_pool, GFP_NOIO); - ablkcipher_request_set_tfm(this_cc->req, cc->tfms[key_index]); - ablkcipher_request_set_callback(this_cc->req, + ablkcipher_request_set_tfm(ctx->req, cc->tfms[key_index]); + ablkcipher_request_set_callback(ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP, - kcryptd_async_done, dmreq_of_req(cc, this_cc->req)); + kcryptd_async_done, dmreq_of_req(cc, ctx->req)); } /* @@ -756,28 +901,26 @@ static void crypt_alloc_req(struct crypt_config *cc, static int crypt_convert(struct crypt_config *cc, struct convert_context *ctx) { - struct crypt_cpu *this_cc = this_crypt_config(cc); int r; atomic_set(&ctx->cc_pending, 1); - while(ctx->idx_in < ctx->bio_in->bi_vcnt && - ctx->idx_out < ctx->bio_out->bi_vcnt) { + while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) { crypt_alloc_req(cc, ctx); atomic_inc(&ctx->cc_pending); - r = crypt_convert_block(cc, ctx, this_cc->req); + r = crypt_convert_block(cc, ctx, ctx->req); switch (r) { /* async */ case -EBUSY: wait_for_completion(&ctx->restart); - INIT_COMPLETION(ctx->restart); + reinit_completion(&ctx->restart); /* fall through*/ case -EINPROGRESS: - this_cc->req = NULL; + ctx->req = NULL; ctx->cc_sector++; continue; @@ -845,7 +988,7 @@ static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size, size -= len; } - if (!clone->bi_size) { + if (!clone->bi_iter.bi_size) { bio_put(clone); return NULL; } @@ -876,6 +1019,7 @@ static struct dm_crypt_io *crypt_io_alloc(struct crypt_config *cc, io->sector = sector; io->error = 0; io->base_io = NULL; + io->ctx.req = NULL; atomic_set(&io->io_pending, 0); return io; @@ -901,6 +1045,8 @@ static void crypt_dec_pending(struct dm_crypt_io *io) if (!atomic_dec_and_test(&io->io_pending)) return; + if (io->ctx.req) + mempool_free(io->ctx.req, cc->req_pool); mempool_free(io, cc->io_pool); if (likely(!base_io)) @@ -985,7 +1131,7 @@ static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp) crypt_inc_pending(io); clone_init(io, clone); - clone->bi_sector = cc->start + io->sector; + clone->bi_iter.bi_sector = cc->start + io->sector; generic_make_request(clone); return 0; @@ -1031,9 +1177,9 @@ static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async) } /* crypt_convert should have filled the clone bio */ - BUG_ON(io->ctx.idx_out < clone->bi_vcnt); + BUG_ON(io->ctx.iter_out.bi_size); - clone->bi_sector = cc->start + io->sector; + clone->bi_iter.bi_sector = cc->start + io->sector; if (async) kcryptd_queue_io(io); @@ -1048,7 +1194,7 @@ static void kcryptd_crypt_write_convert(struct dm_crypt_io *io) struct dm_crypt_io *new_io; int crypt_finished; unsigned out_of_pages = 0; - unsigned remaining = io->base_bio->bi_size; + unsigned remaining = io->base_bio->bi_iter.bi_size; sector_t sector = io->sector; int r; @@ -1070,9 +1216,9 @@ static void kcryptd_crypt_write_convert(struct dm_crypt_io *io) } io->ctx.bio_out = clone; - io->ctx.idx_out = 0; + io->ctx.iter_out = clone->bi_iter; - remaining -= clone->bi_size; + remaining -= clone->bi_iter.bi_size; sector += bio_sectors(clone); crypt_inc_pending(io); @@ -1114,8 +1260,7 @@ static void kcryptd_crypt_write_convert(struct dm_crypt_io *io) crypt_inc_pending(new_io); crypt_convert_init(cc, &new_io->ctx, NULL, io->base_bio, sector); - new_io->ctx.idx_in = io->ctx.idx_in; - new_io->ctx.offset_in = io->ctx.offset_in; + new_io->ctx.iter_in = io->ctx.iter_in; /* * Fragments after the first use the base_io @@ -1274,9 +1419,12 @@ static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode) static int crypt_setkey_allcpus(struct crypt_config *cc) { - unsigned subkey_size = cc->key_size >> ilog2(cc->tfms_count); + unsigned subkey_size; int err = 0, i, r; + /* Ignore extra keys (which are used for IV etc) */ + subkey_size = (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count); + for (i = 0; i < cc->tfms_count; i++) { r = crypto_ablkcipher_setkey(cc->tfms[i], cc->key + (i * subkey_size), @@ -1326,8 +1474,6 @@ static int crypt_wipe_key(struct crypt_config *cc) static void crypt_dtr(struct dm_target *ti) { struct crypt_config *cc = ti->private; - struct crypt_cpu *cpu_cc; - int cpu; ti->private = NULL; @@ -1339,13 +1485,6 @@ static void crypt_dtr(struct dm_target *ti) if (cc->crypt_queue) destroy_workqueue(cc->crypt_queue); - if (cc->cpu) - for_each_possible_cpu(cpu) { - cpu_cc = per_cpu_ptr(cc->cpu, cpu); - if (cpu_cc->req) - mempool_free(cpu_cc->req, cc->req_pool); - } - crypt_free_tfms(cc); if (cc->bs) @@ -1364,9 +1503,6 @@ static void crypt_dtr(struct dm_target *ti) if (cc->dev) dm_put_device(ti, cc->dev); - if (cc->cpu) - free_percpu(cc->cpu); - kzfree(cc->cipher); kzfree(cc->cipher_string); @@ -1409,6 +1545,7 @@ static int crypt_ctr_cipher(struct dm_target *ti, return -EINVAL; } cc->key_parts = cc->tfms_count; + cc->key_extra_size = 0; cc->cipher = kstrdup(cipher, GFP_KERNEL); if (!cc->cipher) @@ -1421,13 +1558,6 @@ static int crypt_ctr_cipher(struct dm_target *ti, if (tmp) DMWARN("Ignoring unexpected additional cipher options"); - cc->cpu = __alloc_percpu(sizeof(*(cc->cpu)), - __alignof__(struct crypt_cpu)); - if (!cc->cpu) { - ti->error = "Cannot allocate per cpu state"; - goto bad_mem; - } - /* * For compatibility with the original dm-crypt mapping format, if * only the cipher name is supplied, use cbc-plain. @@ -1460,13 +1590,6 @@ static int crypt_ctr_cipher(struct dm_target *ti, goto bad; } - /* Initialize and set key */ - ret = crypt_set_key(cc, key); - if (ret < 0) { - ti->error = "Error decoding and setting key"; - goto bad; - } - /* Initialize IV */ cc->iv_size = crypto_ablkcipher_ivsize(any_tfm(cc)); if (cc->iv_size) @@ -1493,18 +1616,33 @@ static int crypt_ctr_cipher(struct dm_target *ti, cc->iv_gen_ops = &crypt_iv_null_ops; else if (strcmp(ivmode, "lmk") == 0) { cc->iv_gen_ops = &crypt_iv_lmk_ops; - /* Version 2 and 3 is recognised according + /* + * Version 2 and 3 is recognised according * to length of provided multi-key string. * If present (version 3), last key is used as IV seed. + * All keys (including IV seed) are always the same size. */ - if (cc->key_size % cc->key_parts) + if (cc->key_size % cc->key_parts) { cc->key_parts++; + cc->key_extra_size = cc->key_size / cc->key_parts; + } + } else if (strcmp(ivmode, "tcw") == 0) { + cc->iv_gen_ops = &crypt_iv_tcw_ops; + cc->key_parts += 2; /* IV + whitening */ + cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE; } else { ret = -EINVAL; ti->error = "Invalid IV mode"; goto bad; } + /* Initialize and set key */ + ret = crypt_set_key(cc, key); + if (ret < 0) { + ti->error = "Error decoding and setting key"; + goto bad; + } + /* Allocate IV */ if (cc->iv_gen_ops && cc->iv_gen_ops->ctr) { ret = cc->iv_gen_ops->ctr(cc, ti, ivopts); @@ -1681,11 +1819,12 @@ static int crypt_map(struct dm_target *ti, struct bio *bio) if (unlikely(bio->bi_rw & (REQ_FLUSH | REQ_DISCARD))) { bio->bi_bdev = cc->dev->bdev; if (bio_sectors(bio)) - bio->bi_sector = cc->start + dm_target_offset(ti, bio->bi_sector); + bio->bi_iter.bi_sector = cc->start + + dm_target_offset(ti, bio->bi_iter.bi_sector); return DM_MAPIO_REMAPPED; } - io = crypt_io_alloc(cc, bio, dm_target_offset(ti, bio->bi_sector)); + io = crypt_io_alloc(cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector)); if (bio_data_dir(io->base_bio) == READ) { if (kcryptd_io_read(io, GFP_NOWAIT)) @@ -1817,7 +1956,7 @@ static int crypt_iterate_devices(struct dm_target *ti, static struct target_type crypt_target = { .name = "crypt", - .version = {1, 12, 1}, + .version = {1, 13, 0}, .module = THIS_MODULE, .ctr = crypt_ctr, .dtr = crypt_dtr, @@ -1857,6 +1996,6 @@ static void __exit dm_crypt_exit(void) module_init(dm_crypt_init); module_exit(dm_crypt_exit); -MODULE_AUTHOR("Christophe Saout <christophe@saout.de>"); +MODULE_AUTHOR("Jana Saout <jana@saout.de>"); MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption"); MODULE_LICENSE("GPL"); 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